Magnetic recording and reproducing device

Abstract

This invention relates to a magnetic recording and reproducing device in which automatic settings of optimum recording bias current, optimum recording level and optimum recording equalization characteristic are successively accomplished in this order. The settings of the optimum recording conditions are achieved with high accuracy within short period of time by a computer control using a microprocessor.

We claim: 
     
       1. A magnetic recording and reproducing device comprising: means for setting an optimum recording bias current, said optimum recording bias current being set by varying a recording bias current at arbitrary time intervals and digitally storing and operating reference recording/reproducing signals corresponding to the recording bias current thus varied; means for setting an optimum recording level, said optimum recording level being set by varying a recording level at arbitrary time intervals and comparing reference recording/reproducing signals corresponding to the record level thus varied with a reference level; and means for setting an optimum recording equalization characteristic, said optimum recording equalization characteristic being set by varying a recording equalization characteristic at arbitrary time intervals and comparing high frequency band reference recording/reproducing signals corresponding to the record equalization characteristic thus varied. 
     
     
       2. The device as claimed in claim 1 characterized in that said means for setting the optimum recording level is operated after said means for setting the optimum recording bias current is operated, and finally said means for setting the optimum recording equalizer characteristic is operated. 
     
     
       3. The device as claimed in claim 1 wherein said means for setting the optimum recording level comprises means for obtaining at least two optimum recording level data and subjecting said data to additive average in digital mode, to obtain a finally optimum recording level current. 
     
     
       4. The device as claimed in claim 1 wherein said means for setting the optimum recording equalization characteristic comprises means for obtaining at least two optimum recording equalizer characteristic data and subjecting said data to additive average in digital mode, to obtain a finally optimum recording equalization characteristic. 
     
     
       5. The device as claimed in claim 1 wherein said means for setting the optimum recording bias current comprises means for obtaining at least two optimum recording bias current data and subjecting said data to additive average in digital mode, to obtain a finally optimum recording bias current. 
     
     
       6. A magnetic recording and reproducing device comprising: means for varying a recording bias current at arbitrary time intervals; means for recording and reproducing a reference recording signal; means for storing in a register analog-to-digital converted reference recording/reproducing signals corresponding to said recording bias current; and operation means for reading out the content stored in the register and subjecting the content to comparison operation, to select an optimum recording bias current, said device being preset by storing in a register a digital signal providing said optimum recording bias current. 
     
     
       7. The device as claimed in claim 6 characterized in that said means for varying operates to be varied every predetermined period of time in response to an operational instruction from a microprocessor. 
     
     
       8. The device as claimed in claim 6 characterized in that said means for varying operates to vary said recording bias current in digital mode in response to the operational instruction from the microprocessor. 
     
     
       9. The device as claimed in claim 6 characterized in that said operation means comprises instruction means in which the reference recording/reproducing signals corresponding to the values of said recording bias current from the minimum value to the maximum value are subjected to analog-to-digital conversion, drop-out is detected by an operation based on the content stored in the register, and when the drop-out is detected, the operation is determined as ineffective information and returns to the initial operation or said drop-out is processed as ineffective information. 
     
     
       10. A magnetic recording and reproducing device comprising: means for varying a recording bias current at arbitrary time intervals; means for recording and reproducing a reference recording signal; means for storing in a register analog-to-digital converted reference recording/reproducing signals corresponding to the recording bias current; operation means for reading out the content stored in the register and subjecting the content to comparison operation, to select an optimum recording bias current; and control means for repeatedly carrying at least twice a routine that said optimum recording bias current is selected, the optimum recording bias currents obtained through the repetition of said routine being subjected to additive average to obtain a finally optimum recording bias current. 
     
     
       11. A magnetic recording and reproducing device comprising: means for setting an optimum recording bias current, said optimum recording bias current being set by varying a recording bias current at arbitrary time intervals and digitally storing and operating reference recording/reproducing signals corresponding to the recording bias current thus varied; means for setting an optimum recording level, said optimum recording level being set by varying a recording level at arbitrary time intervals and comparing reference recording/reproducing signals corresponding to the recording level thus varied with a reference level; means for setting an optimum recording equalization characteristic, said optimum recording equalization characteristic being set by varying a recording equalization characteristic at arbitrary time intervals and comparing high frequency band reference recording/reproducing signals corresponding to the recording equalization characteristic thus varied; and means for storing data representative of said optimum recording bias current, optimum recording level and optimum recording equalization characteristic in digital mode separately according to the kinds of magnetic tapes, said data being selectable as required.